Competition, predation and environmental factors as structuring
... in the lakes studied. However, abiotic factors such as conductivity and pH were also found to affect fish community structure. In a larger data set of Finnish lakes (including the data used here), Tonn et al. (1990) found that the relative abundance of roach depended on lake isolation, pH, lake area ...
... in the lakes studied. However, abiotic factors such as conductivity and pH were also found to affect fish community structure. In a larger data set of Finnish lakes (including the data used here), Tonn et al. (1990) found that the relative abundance of roach depended on lake isolation, pH, lake area ...
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... Valuing Aquatic Ecosystem Services: Applications to Recreational Fisheries in Oklahoma, Oklahoma Clean Lakes and Watersheds Annual Meeting, Stillwater, Oklahoma, March 2016. ...
... Valuing Aquatic Ecosystem Services: Applications to Recreational Fisheries in Oklahoma, Oklahoma Clean Lakes and Watersheds Annual Meeting, Stillwater, Oklahoma, March 2016. ...
Community Ecology
... pond-breeding salamanders… In this course any collection of two or more species is “fair game” for close scrutiny ...
... pond-breeding salamanders… In this course any collection of two or more species is “fair game” for close scrutiny ...
test bIodIversIty – why It mAtters
... Biological diversity or biodiversity is defined as the diversity, or range of difference, within any given species, between species, and between ecosystems.1 These living organisms may interact in very complex ways. Generally, biodiversity can be used as a measure of the overall health of a particul ...
... Biological diversity or biodiversity is defined as the diversity, or range of difference, within any given species, between species, and between ecosystems.1 These living organisms may interact in very complex ways. Generally, biodiversity can be used as a measure of the overall health of a particul ...
Understanding ecosystem dynamics for conservation of
... then one should expect the effects of exotic predators to be even more marked. This is clearly demonstrated where exotic predators such as red fox Vulpes vulpes in Australia, stoats Mustela erminea in New Zealand and a plethora of other species on islands in the Pacific and Indian oceans, supported ...
... then one should expect the effects of exotic predators to be even more marked. This is clearly demonstrated where exotic predators such as red fox Vulpes vulpes in Australia, stoats Mustela erminea in New Zealand and a plethora of other species on islands in the Pacific and Indian oceans, supported ...
University of Groningen Holism and reductionism in biology
... individuals may fall a prey to all sorts of predators, parasites or diseases. All such factors may result in there being at some moment more deaths than births such that population growth decreases or becomes negative (that is, r = (l - m) becomes negative). The simplest additional assumption that c ...
... individuals may fall a prey to all sorts of predators, parasites or diseases. All such factors may result in there being at some moment more deaths than births such that population growth decreases or becomes negative (that is, r = (l - m) becomes negative). The simplest additional assumption that c ...
V C F
... 1. Determine what facets of the temperature regime (such as temperature maxima and averages) are biologically significant and what data must be collected to feed into developing metrics. 2. Develop a suite of metrics that characterize the suitability of the summer temperature regime for coldwater fi ...
... 1. Determine what facets of the temperature regime (such as temperature maxima and averages) are biologically significant and what data must be collected to feed into developing metrics. 2. Develop a suite of metrics that characterize the suitability of the summer temperature regime for coldwater fi ...
Local diversity reduces infection risk across multiple
... a replicated test of the hypothesis that local biodiversity affects infection risk in aquatic systems. Our analysis focuses exclusively on the cercarial transmission step of several trematode species. We use two individual-level measures of infection risk in target second intermediate hosts, prevale ...
... a replicated test of the hypothesis that local biodiversity affects infection risk in aquatic systems. Our analysis focuses exclusively on the cercarial transmission step of several trematode species. We use two individual-level measures of infection risk in target second intermediate hosts, prevale ...
Diversity, productivity and temporal stability in the economies ARTICLE IN PRESS
... from microeconomic views of optimal foraging and competition among individuals to macroeconomic predictions of such ecosystem processes as productivity, efficiency of resource use, and temporal stability (e.g., [6,12,13,15,19,26,28,29,31]). Consumer–resource interactions, specifically competition amon ...
... from microeconomic views of optimal foraging and competition among individuals to macroeconomic predictions of such ecosystem processes as productivity, efficiency of resource use, and temporal stability (e.g., [6,12,13,15,19,26,28,29,31]). Consumer–resource interactions, specifically competition amon ...
Marine Science - Mathematics and Statistics
... 2009; Datta et al., 2010). The paper develops an approach taken by Rochet and Benoı̂t (2011) who found variation in abundance over time in simulations of size spectra increased when fishing was made more size selective, and/or larger fish were targetted. The reason for turning to size-spectra models ...
... 2009; Datta et al., 2010). The paper develops an approach taken by Rochet and Benoı̂t (2011) who found variation in abundance over time in simulations of size spectra increased when fishing was made more size selective, and/or larger fish were targetted. The reason for turning to size-spectra models ...
Benthic grazers and suspension feeders: Which one assumes the
... 0.32 m g ash free dry weight (AFDW). In this size range, the small prosobranch Hydrobia ulvae was the dominant species, showing maximal biomass as well as secondary production, respiration and energy flow in the seagrass-bed. The second peak of the size-frequency histogram was formed by the polychae ...
... 0.32 m g ash free dry weight (AFDW). In this size range, the small prosobranch Hydrobia ulvae was the dominant species, showing maximal biomass as well as secondary production, respiration and energy flow in the seagrass-bed. The second peak of the size-frequency histogram was formed by the polychae ...
Species Profile - Atlantic States Marine Fisheries Commission
... Each spring, as water temperatures slowly warm, fishermen and nature-lovers know what’s moving into the rivers. Following the scent of the water, American shad hone in on streams where they were born. These small fish travel up to 2,000 miles from their oceanic feeding grounds to their freshwater sp ...
... Each spring, as water temperatures slowly warm, fishermen and nature-lovers know what’s moving into the rivers. Following the scent of the water, American shad hone in on streams where they were born. These small fish travel up to 2,000 miles from their oceanic feeding grounds to their freshwater sp ...
Managing conflicts arising from fisheries enhancements based on
... transferred from Lake Tanganyika, where it is an endemic small pelagic species, to Lake Kariba during 1967–1968 to fill the vacant pelagic niche in the newly flooded reservoir (Marshall, 1991). It was later introduced into Lake Itezhi-tezhi in the early 1990s and dispersed down the Zambezi River to ...
... transferred from Lake Tanganyika, where it is an endemic small pelagic species, to Lake Kariba during 1967–1968 to fill the vacant pelagic niche in the newly flooded reservoir (Marshall, 1991). It was later introduced into Lake Itezhi-tezhi in the early 1990s and dispersed down the Zambezi River to ...
Ecological Concepts, Principles and Applications
... source for many animals, including grizzly bears that drag the carcasses of salmon into the forest, adding beneficial nitrogen into forest soils where it is limited.14 Another example is sea otters that feed on sea urchins, which in turn feed on kelp. By limiting the number of sea urchins, the sea o ...
... source for many animals, including grizzly bears that drag the carcasses of salmon into the forest, adding beneficial nitrogen into forest soils where it is limited.14 Another example is sea otters that feed on sea urchins, which in turn feed on kelp. By limiting the number of sea urchins, the sea o ...
AMPHIPODS AS FOOD SOURCES FOR HIGHER TROPHIC
... to estimate that about 60 millions of tons of these crustaceans are consumed each year in the area, i.e. about 1.6 t.km-2.yr-1. By comparison, the consumption of krill by all its predators in the Southern Ocean has been estimated to about 250 Mt.yr-1 (Everson 1977, Miller & Hampton 1989), while annu ...
... to estimate that about 60 millions of tons of these crustaceans are consumed each year in the area, i.e. about 1.6 t.km-2.yr-1. By comparison, the consumption of krill by all its predators in the Southern Ocean has been estimated to about 250 Mt.yr-1 (Everson 1977, Miller & Hampton 1989), while annu ...
Trophically Unique Species Are Vulnerable to Cascading Extinction Linköping University Postprint
... tends to interact with connectance. In sparsely connected communities, extinction of a top predator is less likely to cause secondary extinctions than extinction of a basal species (Borrvall et al. 2000; Quince et al. 2005; Eklöf and Ebenman 2006). However, in more highly connected communities, ext ...
... tends to interact with connectance. In sparsely connected communities, extinction of a top predator is less likely to cause secondary extinctions than extinction of a basal species (Borrvall et al. 2000; Quince et al. 2005; Eklöf and Ebenman 2006). However, in more highly connected communities, ext ...
Food Webs, Competition Graphs, and Habitat Formation
... Early on, the relationships between mathematics and the physical sciences have been appreciated and often have been used as a reason to study mathematics and its applications to the physical sciences. However, the interplay between mathematics and the biological sciences was understood by only a few ...
... Early on, the relationships between mathematics and the physical sciences have been appreciated and often have been used as a reason to study mathematics and its applications to the physical sciences. However, the interplay between mathematics and the biological sciences was understood by only a few ...
Fish in farm dams - Rural Residential Living
... About 100 species of freshwater crayfish are native to Australia. They vary in their habitat and food requirements, and should generally be stocked only in areas where they occur naturally – the possible effects on local crayfish and other animals and ecology are unknown, and it can be very difficul ...
... About 100 species of freshwater crayfish are native to Australia. They vary in their habitat and food requirements, and should generally be stocked only in areas where they occur naturally – the possible effects on local crayfish and other animals and ecology are unknown, and it can be very difficul ...
Counting the books while the library burns: why conservation
... including learning about a species’ ecology and population biology, reporting on the state of biodiversity, and estimating the state of (or detecting changes in) populations so that appropriate actions can be taken (Yoccoz et al. 2001). However, when a monitoring program is funded under the specific ...
... including learning about a species’ ecology and population biology, reporting on the state of biodiversity, and estimating the state of (or detecting changes in) populations so that appropriate actions can be taken (Yoccoz et al. 2001). However, when a monitoring program is funded under the specific ...
Marine Aquarium Fishery Management Plan
... The Government of Tonga began promoting reef resources for generating foreign revenue in the mid 1980s. These particular reef resources include small inedible 1 fish, corals (soft and hard), invertebrates and live rocks (rubbles, dead rocks, aquarium rocks). The purpose of this fishery is aimed at o ...
... The Government of Tonga began promoting reef resources for generating foreign revenue in the mid 1980s. These particular reef resources include small inedible 1 fish, corals (soft and hard), invertebrates and live rocks (rubbles, dead rocks, aquarium rocks). The purpose of this fishery is aimed at o ...
Stock assessment – the basics The science of counting fish
... this year, compared to last year, it is very probable that the fish stock in the sea is twice as large as the year before. Fishermen are at sea throughout the entire year, so they can provide more information on catch rates throughout different seasons than research vessels do. However, commercial f ...
... this year, compared to last year, it is very probable that the fish stock in the sea is twice as large as the year before. Fishermen are at sea throughout the entire year, so they can provide more information on catch rates throughout different seasons than research vessels do. However, commercial f ...
Sustaining the Saco
... system described by predators and their prey. Primary producers (i.e., plants) capture energy from the sun, and then the energy is transferred to animals through herbivory and predation. Beyond simply mapping predator-prey relationships, a food web characterizes the relative importance of each prey ...
... system described by predators and their prey. Primary producers (i.e., plants) capture energy from the sun, and then the energy is transferred to animals through herbivory and predation. Beyond simply mapping predator-prey relationships, a food web characterizes the relative importance of each prey ...
A declining species has to be added to the official list of endangered
... A 1973 conference in Washington led to the signing of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which restricted international commerce in plant and animal species believed to be actually or potentially harmed by trade. Later that year, the Endanger ...
... A 1973 conference in Washington led to the signing of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which restricted international commerce in plant and animal species believed to be actually or potentially harmed by trade. Later that year, the Endanger ...
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource. The term applies to natural resources such as: wild medicinal plants, grazing pastures, game animals, fish stocks, forests, and water aquifers.In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at a rate that is unsustainable, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined somewhat differently in fisheries, hydrology and natural resource management.Overexploitation can lead to resource destruction, including extinctions. However it is also possible for overexploitation to be sustainable, as discussed below in the section on fisheries. In the context of fishing, the term overfishing can be used instead of overexploitation, as can overgrazing in stock management, overlogging in forest management, overdrafting in aquifer management, and endangered species in species monitoring. Overexploitation is not an activity limited to humans. Introduced predators and herbivores, for example, can overexploit native flora and fauna.